低浓度SO_2检测管的研制

通过对常见的几种检测管法的比较，筛选出灵敏度较高的亚硝基铁氰化钠法；同时筛选出载体为６０—８０目的素陶瓷，指示剂浓度为２０％。玻璃管内径为２．０—２．３ｍｍ，采气速度为０．３（Ｌ／ｍｉｎ），采样体积为１２Ｌ，以此条件进行实验．结果表明，检测管变色长度对应ＳＯ２浓度的相关性很好；变异系数均小于１１０％，检测的重现性较好。检测管的测定值与理论值的平均相对误差为５．０９％（＜±１５％），最大相对误差为７．１３％（＜±２５％），准确度较高．测定结果可靠；与化学法比较，两者无显著性差异；浓度小于０．１５ｍｇ／ｍ３的Ｈ２Ｓ及浓度小于０．０１ｍｇ／ｍ３的ＮＯ２对ＳＯ２检测管无干扰．

preparation of detection tube of low concentration SO_2

A highly sensitive method was selected by comparing several methods of detection tube.The experimental conditions were as follows:The carrier is ceramics of 60-80 mesh,the concentration of indicator is 20%,the internal diameter of glass tube is 2.0-2.3mm,the sampling speed and volume are 0.3L/min and 12L,respectively.The results showed that the prepared detection tube had high sensitivity and accuracy degree(the mean and maximal relative errors are 5.09% and 7.13%,respectively),fine repeatability(coefficient of variation C.V<10%),there was no significant difference in tile determining values between the methods of detection tube and chemical analysis,H2S and NO2,when their concentrations were below 0.15mg/m3 and 0.01mg/m3 respectively,didn't interfere with the determining results.